1. Field of the Invention
This invention relates in general to the field of electronic instrumentation, such as accelerometers.
2. Background Information
Dynamic events of engineering interest include vibration, acceleration, energy dissipation and so forth. For example, dynamic events are associated with the structure of an object in motion subjected to an external force. Dynamic events can be short term in nature, as with energy dissipation within the frame and body of a vehicle involved in a crash test, or in the wing of an aircraft or missile during a particular maneuver.
Capturing dynamic events using equipment such as accelerometers, allocated signal conditioners, amplifiers and recorders, involves modifying the structure of interest to accommodate the equipment. For example, wires can be run between the various components, and power supplied. These modifications can impact the function and operation of the structure of interest. For example, the amount of equipment placed in the device can impact the operation of the equipment due to its location. The installation and removal of the equipment can be time consuming and labor intensive. The instrumentation weight can impact the host structure and subsequent performance during high-G maneuvers.
U.S. Pat. No. 4,745,564 (Tennes) describes a device containing an accelerometer, power supply and memory packaged as produced to measure the acceleration histories of commodities when they are being handled or transported. The device monitors three different coordinate axes, and records accelerations which exceed a limit by the greatest magnitude, and their time of the occurrence.
U.S. Pat. No. Re. 36,200 (Berrian) describes a device for monitoring an externally applied parameter to a selected products. The device includes a housing enclosing a sensor, a monitoring and output network. The monitoring and output network is an integrated circuit, a memory device and an arrangement of LEDs.
U.S. Pat. No. 5,446,659 (Yamawaki) describes a device for recording traffic accident data using an acceleration sensor, angular velocity sensor, memory and a control section. For example, the device records the acceleration and angular velocity of an automobile for a time interval after the detection of an acceleration which exceeds angular velocity threshold.
U.S. Pat. No. 5,610,337 (Nelson) describes measuring the amplitude and frequency of an acceleration using a digital accelerometer manufactured from arrays of micro-mechanical sensing elements designed to detect acceleration in a particular rotational or transitional direction. The sensing elements have size and mass parameters that can be adjusted to vary their frequency response and sensitivity to amplitude of acceleration.